One week down. Seven more to go. Since starting the 8-Week Crash Diet for the Hamptons, I’ve had several side effects: headaches, morning hunger pains and lots of muscle aches.

I also missed “The Swan” and parts of “The Bachelor” because I was too busy squatting and lunging in the gym.

But I have to admit, I feel good. I feel powerful, confident and healthy.

Most of all, I’ve got my eye on the ball. I need to lose an inch off my thighs and flab in my stomach and under my armpits in time for beach season.

But it’s not just the beach that is motivating me: I also want to fit into my favorite pair of jeans from college, which currently sit in my closet, taunting me to lose my excess weight and show the same willpower Jennifer Aniston must have had to lose all her baby fat.

I’m going to wear those jeans very soon.

Also, I am a bridesmaid in two weddings this summer, and I want to look great in those pictures. But most of all, there’s my mom’s new house in the Hamptons, which is moments away from the beach.

People have said to me, “You don’t need to lose weight.” (I’m 5-foot-4 and 130 lbs.)

I see their point, but I’m not in this to lose weight. I’m doing this to get in shape, build muscle and eliminate body fat.

Basically, I want to look hot in a bathing suit.

This week, celebrity trainer Rich Barretta (the mastermind of the 8-Week Crash Diet for the Hamptons) is going to help us all tell the difference between good carbs and bad carbs (he doesn’t believe in eliminating them).

For exercise, he’s going to teach us how to do a proper squat, to tone the butt and thighs (they seem easy enough; most people do them incorrectly).

First: what we should all be eating.

Barretta gives me two stars for my existing diet, but says that I have to eat more carbs in the morning to get me through the day without feeling sluggish or irritable. I need to follow the diet that he devised with his colleague, registered dietician Cindy Sherwin.

“Carbohydrates are [classified by] what’s called a glycemic index – how fast it breaks down into sugar,” Barretta says. “The faster it breaks down into sugar, the sooner you are hungry again.” The end result: You eat more and gain more weight.

Barretta says watermelon, canned beans and Total cereal are bad carbs. Don’t have them if you want to follow his plan. He recommends apples, Special K cereal and angel hair pasta – all carbs that break down slowly.

I asked Barretta if it was all right to have candy every now and then, like a hot fireball or some red licorice.

“No problem,” he said. “But, if you have a bag [of fireballs] a day, it’s bad.”

Pizza is OK, too, though Barretta isn’t thrilled with it. “You won’t gain weight from it, but you’re not going to gain any energy, either,” says Barretta. “It’s not going to make your body physically firmer. It may lead to you having a problem where you’re hungry, or tired.”

As for eating popcorn at the movie theater, he told me to get a small popcorn and share it with someone else. Or bring fruit or a Kashi bar.

“Try not to have bits and pieces of foods at buffets, or when ordering in Chinese food,” he says. “Instead, if you’re going to sample things, put them all together at one time.”

And when you eat, make it a meal.

“Eat Korean, Vietnamese or Thai food,” says Barretta. “They use a lettuce leaf instead of bread. You’re full when you leave, but you haven’t overeaten.”

Also, Barretta warns against falling into the whole-wheat bread trap: It’s not necessarily good for you.

That kind of bread, he says, “is stripped of the wheat. Buy whole-grain bread.”

After Barretta measured my body fat (which dropped only half a millimeter; he promised me a full millimeter), he told me I was getting “much better.”

“You’ve already gotten into the program as far as being aware,” he said. “Stick to it and you’ll have an amazing machine by summer.”

Cheers to that.

8 WEEKS TO THE HAMPTONS

WEEK 2:

RICH SAYS: “If it’s tough to go out without drinking and eating, go into hiding – so there’s a new you to unveil in eight weeks.”

DIET: Eat full meals, with all servings the size of your fist. Candy is allowed, sparingly.

EXERCISE: Get a trainer, so you can learn how to work out properly. Barretta says he sees clients do even simple squats incorrectly all the time.